Spirit of Photography

Mentoring and Learning => Digital Image Processing => Topic started by: keithsnell on January 16, 2009, 11:17:35 AM

Title: Colorize Quick Tutorial
Post by: keithsnell on January 16, 2009, 11:17:35 AM
One of our members asked for a quick tutorial on how to "colorize" an image.  (In digital photography we typically "colorize" an image by converting a color image to black and white, and then adding back color to selected portions of the image.)

Here is the image Sissy sent me:

(http://spiritofphotography.com/coppermine/albums/userpics/10001/IMG_8004_small.jpg)

The first step is to pull the image into Photoshop and convert to Black and White.  We'll do this with an "adjustment layer," like this:

(http://spiritofphotography.com/coppermine/albums/userpics/10001/Colorize-1.jpg)

The "Black and White" conversion dialog provides several alternatives for conversion that are roughly equivalent to the old darkroom methods of Black and White processing.  I've picked the preset that gives the most pleasing "out of the box" rendition of tones and contrast, without too much tweaking:

(http://spiritofphotography.com/coppermine/albums/userpics/10001/Colorize-2.jpg)

Note that using an "adjustment layer" will add a pseudo "adjustment" layer on top of the base layer, as you can see in the Layers palette to the right of the image.  In addition, a "reveal all" mask will automatically be added to the adjustment layer.  (The white rectangle just to the right of the adjustment thumbnail is the "reveal all" mask.)  We can modify this mask to "hide" portions of this B&W adjustment layer and let the original color layer show through.  We'll "hide" portions of the layer by selecting black as the brush color and painting on the mask with a brush.  (When using layer masks, a white area on the mask allows those areas of the corresponding layer to show in the final image, whereas a black area on the mask "hides" the corresponding areas on the layer and allows the layers lower in the stack to show in the final image.)


(http://spiritofphotography.com/coppermine/albums/userpics/10001/Colorize-3.jpg)

Use the drop down Brush menu in the top left of your Photoshop window to adjust the size and "hardness" of the brush.  In this case, set the "hardness" to 0%, which gives a soft-edge brush and allows you to "blend" in the changes you are about to make.  Before you actually paint on the image, it's a good idea to verify that the "layer mask" is selected, and not the actual image layer.  You can determine whether the layer mask is selected by confirming that it has a double border around the mask.  ("Selected" items in the Layers pallete are indicated with a double border.)  Paint over the areas of the image where you want to modify the mask to allow the original color to show through.  In the screen shot below, you can see the small mask thumbnail is black in the areas corresponding to where I've painted with the black brush on the image. 

(http://spiritofphotography.com/coppermine/albums/userpics/10001/Colorize-4.jpg)

This is the final result:

(http://spiritofphotography.com/coppermine/albums/userpics/10001/Colorize-6.jpg)

As an editorial note, this image would have been more successful without the "blown highlights" in the top part of the image.  Using negative exposure compensation and adjusting the flash output to properly illuminate the subject would have been one way of correcting for these blown highlights.

Please let me know if you have any additional questions.

Keith
Title: Re: Colorize Quick Tutorial
Post by: keithsnell on January 18, 2009, 02:52:03 PM
Sissy responded to my post with an email, saying that she had Photoshop Elements 6, which doesn't have the capability to add a Black and White adjustment layer.  As usual with Photoshop (and Elements) there is more than one way to get the same end result. (The B&W adjustment layer method discussed in the original post is one of the most efficient and "elegant" methods, and allows you to easily adjust your results on future edits.) 

Photoshop Elements DOES have the ability to duplicate your background layer, convert that layer to B&W, and then erase through the portions of the top layer where you want the color from the bottom layer to show through.  The disadvantage of using this method is that you won't be able to easily adjust the effects with future edits like you would have if you used an adjustment layer.

Let's go through the steps.  With your image open in Elements:
Duplicate your background layer.  Open the Layers palette, right click on the thumbnail for your background layer and select Duplicate.  You will now have a duplicate layer of your background on the top of the layer stack.  This is the layer we will convert to B&W.

Convert the duplicate layer to B&W.  Select  Enhance > Convert To Black And White.
Select a style option that reflects the content of your image (for example, Portraits or Scenic Landscape), drag the Adjustment Intensity sliders to adjust red, green, blue, or contrast, then click OK.

Erase the portions of the B&W layer where you want color to show through.  Select the eraser tool, set your hardness to zero, adjust your brush size, and then erase through the portions of the top layer where you want the color to show through from the layer below.

That's it!  A simple method for "colorizing" an image using Photoshop Elements.  You can adjust the amount of color that shows through by adjusting the opacity (strength) of the eraser tool to only partially erase the B&W layer, and thus let less color show through in the final image.

Hope this helps those Elements users out there that were struggling to follow my Photoshop instructions in the first post.

Please let me know if you have any additional questions.

Keith